RE: ld-auto-import memory bug fixing

["Ralf Habacker" <Ralf dot Habacker at freenet dot de>]

I have looked into the relating stuff and found, that for any section of any
input bfd a symbol tab is allocated.
For this I have two questions:

1. I recognized, that for any input file read by bfd one symboltab is present,
not one for any section. Isn't it 	?
If this is true (and it seems so, because I have applied a patch and have
compiled about 20 dll's with it), I have
found a way to solve this problem.  (moving symboltable allocating in the first
for loop)

(This patch contains some debugging stuff, which needs other files patch. It is
for dicsussion only)

pe-dll.c
   for (b = info->input_bfds; b; b = b->link_next)
     {
-      arelent **relocs;
-      int relsize, nrelocs, i;
+         int nsyms, symsize;
+         asymbol **symbols;

+         symsize = bfd_get_symtab_upper_bound (b);
+         symbols = (asymbol **) xmalloc (symsize);
+         nsyms = bfd_canonicalize_symtab (b, symbols);
+
       for (s = b->sections; s; s = s->next)
        {
-         asymbol **symbols;
-         int nsyms, symsize;
+      int relsize, nrelocs, i;
+           arelent **relocs;
          int flags = bfd_get_section_flags (b, s);

          /* Skip discarded linkonce sections */
          if (flags & SEC_LINK_ONCE
-             && s->output_section == bfd_abs_section_ptr)
+                     && s->output_section == bfd_abs_section_ptr) {
+                               if (pe_dll_extra_pe_debug & 4)
+                                       printf("\t section->name=%s -->
ignored\n",s->name);
            continue;
-
+                       }
          current_sec=s;

-         symsize = bfd_get_symtab_upper_bound (b);
-         symbols = (asymbol **) xmalloc (symsize);
-         nsyms = bfd_canonicalize_symtab (b, symbols);
-
          relsize = bfd_get_reloc_upper_bound (b, s);
          relocs = (arelent **) xmalloc ((size_t) relsize);
          nrelocs = bfd_canonicalize_reloc (b, s, relocs, symbols);

2. Relating to this bug, I have found that allocating symbol tables is done
several times in ld. Using a symbol
   cache would be save much memory.

			pe_find_data_imports ()
	ei386pe.c:         symsize = bfd_get_symtab_upper_bound (b);

			gld_i386pe_after_open ()
	ei386pe.c:         symsize = bfd_get_symtab_upper_bound (is->the_bfd);

			pe_walk_relocs_of_symbol (info, name, cb)
	pe-dll.c:         symsize = bfd_get_symtab_upper_bound (b);

			process_def_file (abfd, info)
	pe-dll.c:         symsize = bfd_get_symtab_upper_bound (b);

			generate_reloc (abfd, info)
	pe-dll.c:         symsize = bfd_get_symtab_upper_bound (b);

	ldcref.c:      symsize = bfd_get_symtab_upper_bound (abfd);
	ldmain.c:         symsize = bfd_get_symtab_upper_bound (abfd);
	ldmisc.c:                   symsize = bfd_get_symtab_upper_bound (abfd);

What about creating a symbol cache list in ld using pointer to loaded symbols
tables or by extending bfd structure with a pointer to a "symbol cache entry",
which can be filled by client code and later reused by other code.
Extending bfd would minimize the overhead to handle this cache, so I think this
would be the best way.
I have to say one limitation to this. Such cached symbol tables should not be
manipulated. They should be used only read only. Is this real ?

Regards Ralf